It is often desirable for a patient to be able to monitor his own blood pressure throughout certain times of the day. This is especially important for a cardiac patient who must obtain specific blood pressure data when he feels certain symptoms coming on so that a physician can later review the data to determine the progress of the patient by correlating a description of the symptoms with the blood pressure measurements.
A number of attempts have been made to provide apparatus to allow a patient to take his blood pressure readings at different times throughout a day or a period of several days. The following U.S. Patents disclose blood pressure recorders, none necessarily for use by unattended patients: Nos. 1,934,124; 2,186,517; 2,447,018; 2,989,051; 3,557,779 and 3,623,478. Of these patents, U.S. Pat. No. 3,557,779 probably is the most pertinent with respect to a patient taking his own blood pressure. However, this patent reveals a device which is to be carried entirely on the limb, such as the arm of the patient, and is required to be so compact that accuracy and ease of operation must be sacrificed, thereby limiting the credibility of the results obtainable with the use of the device. The other patents disclose structures which are relatively complex and would require an additional person in attendance to operate them. These patents disclose single measurement devices and are not intended to be used by ambulatory patients where it is necessary to record and store a series of measurements.
As a result of the limitations of prior devices mentioned above, a need has arisen for an improved blood pressure recorder which permits a patient to automatically take and record his own blood pressure in a manner such that the blood pressure readings throughout various intervals in a day or period of several days can be readily analyzed for diagnostic or other purposes.